Electrical connector

ABSTRACT

A quick-disconnect electrical connector that includes two cylindrical plug members, a male half and a female half. Each plug member has conductor pins mounted therein that are joined when the halves are assembled. The female plug member has a keyball that must slide in a slot milled in the male plug member during assembly, thus assuring correct alignment of the plug members. The interior of the connector is sealed off by an O-ring in the female plug that contacts the male plug member after assembly is complete. The length of the cylindrical plug members and the conductor pins mounted therein are such that when the two halves of the connector are being assembled or separated and the connection between the conductor pins is made or broken with the male plug member still in the female plug member.

United States Patent Horton [451 Apr. 25, 1972 [54] ELECTRICAL CONNECTOR [21] Appl. No.: 80,612

Primary Examiner-Joseph H. McGlynn AttorneyL. D. Wofford, Jr., Charles C. Wells and John R. Manning ABSTRACT A quick-disconnect electrical connector that includes two cylindrical plug members, a male half and a female half. Each plug member has conductor pins mounted therein that are joined when the halves are assembled. The female plug member has a keyball that must slide in a slot milled in the male plug member during assembly, thus assuring correct alignment of the plug members. The interior of the connector is sealed off by an O-ring in the female plug that contacts the male plug member after assembly is complete. The length of the cylindrical plug members and the conductor pins mounted therein are such that when the two halves of the connector are being assembled or separated and the connection between the conductor pins is made or broken with the male plug member still in the female plug member.

10 Claims, 2 Drawing Figures PATENTEDAPRZS 1912 3, 658 250 Wei INVENTOR ROBERT F. HORTON BY May/M41 ATTORNEY ELECTRICAL CONNECTOR ORIGIN OF THE INVENTION The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to electrical connectors. More particularly, the invention is a connector in which improved fabrication techniques are used so as to reduce production costs and novel sealing methods are employed to achieve improved reliability and safety.

2. Description of the Prior Art There are many types and sizes of electrical connectors available. However the use of electrical connectors is extensive and the demand for better and cheaper connectors is ever present. For this reason much development effort is constantly directed toward the design of an improved connector having a reasonable cost. Some of the requirements or at least desirable characteristics of electrical connectors are, ease of assembly and disassembly, and sealing the interior of the connector to prevent the entry of moisture or corrosive gases. Moisture in a connector can cause short circuiting between conductors in the connector as well as corrosion and result in unreliable electrical connections. In addition, a connector to be used in an explosive environment must include provision for shielding the conductors during assembly and disassembly or otherwise the arcing which commonly occurs upon breaking an electrical connection may result in an explosion. While these are recognized problems which are dealt with in many ways by prior art devices, the present invention is an improved and novel connector that treats these problems in a manner that results in an economical connector.

SUMMARY OF THE INVENTION The invention is an electrical connector that includes two plug members, a female half and a male half. Each plug half has electrical conductors mounted therein that are joined when the plug halves are assembled together. Proper alignment of the assembled plug halves is assured by a keyball mounted in the female plug half so as to mate with a slot or keyway formed in the male plug half. Assembly can be accomplished only when the slot and keyball are in alignment. The interior of the connector is sealed by installing an O-ring seal in a groove formed in an interior surface of the female plug member. The O-ring is positioned so that it is engaged by one end of the male plug member so as to effectively seal off the interior of the connector against the entry of moisture and/or other corrosive materials. The connector is self shielding in that the length of the male and female plug members, and the conductor pins mounted therein, are such that the electrical connection between the conductor pins is made or broken while the male plug member is still inserted in the female plug member. The two plug members are releasably locked together by several locking balls mounted in the female plug and held in place by a slidable locking collar. The locking balls fit into cavities formed into the male plug member. The locking collar has a groove that can be aligned with the locking balls to permit forcing the locking balls out of the cavities in the male plug member thus releasing it for removal from the female plug member.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross sectional view of the connector with the male plug member fully inserted in the female plug member.

FIG. 2 is a view, partially sectioned, illustrating how the electrical connection between the conductor pins can be made while the male plug member remains partially inserted in the female plug member.

DETAILED DESCRIPTION OF THE INVENTION and a male plug member 14 adapted to be inserted into the female plug member.

Plug member 12 includes a first cylindrical section 16 that substantially surrounds plug member 14 and a second cylindrical section 18 having external threads 19 formed thereon. A potting boot 20 is threaded onto section 18. Plug member 12 includes a transverse wall 22 between cylindrical sections 16 and 18 and a plurality of electrical conductor pins 24 are mounted through wall 22. The conductor pins are mounted in place in wall 22 by a suitable dielectric material 23, such as glass, that secures the conductor pins in place as well as insulates the conductor pins from the female plug member. Any desired number of conductor pins can be utilized in the connector. A crimp or weld cup 26 is mounted on the end of each of the conductor pins 24 to facilitate wire connections thereto.

After such wire connection is made the interior of potting boot 20 can be filled with a suitable potting compound.

Plug member 12 has a slidable locking collar 28 mounted thereon so as to surround sections 16. A spring 30 is positioned between collar 28 and a radially extending shoulder 32 on plug 12 so as to normally bias locking collar 28 away from shoulder 32. Snap ring 33 retains collar 28 in place (FIG. 2). Collar 28 is provided with a circular groove 34 which when aligned with locking balls 36 permits outward movement of locking balls 36. The locking balls are normally positioned in apertures 37 formed in section 16 of the female plug member. In the drawing only one locking ball is shown in each FIGURE, but it should be understood that a number of locking balls can be spaced around the periphery of the female plug member. Three locking balls were used in the invention. An O-ring groove 36 is formed in the interior of cylindrical section 16 and an O-ring seal 40 9s mounted in this groove.

The male plug member comprises a cylindrical section 42 that slides into cylindrical section 16 of the female plug. Cylindrical section 42 is closed by a vertical wall portion 44 that includes a radially extending flange like portion 46 which functions as a stop to limit the travel of the male plug member into the female plug member. A plurality of electrical conductor pins 48 are mounted in wall 44 and insulated therefrom by a suitable dielectric material 50. Pins 48 slide into sockets formed in the ends of pins 24 when the male plug is inserted into the female plug. The sockets are shown in phantom in FIG. 1.

Alignment of the plug members during assembly is assured by a keyball 50 that is mounted in an opening 52 formed in section 16 of the female plug member. The keyball slides in a slot or keyway 54 that has been milled in the exterior surface of plug 14. The purpose of keyball 50 and slot 54 is to assure that plug 14 is properly aligned with respect to plug 12 when assembled thus assuring proper connections of the conductor pins 24 and 48.

The use of a keyball, rather than a key that is integrally formed on a cylindrical section 16 of the female plug member, in conjunction with slot 54 facilitates assembly of the connector. HOwever, the main advantage to using a keyball is that it makes for cheaper construction by eliminating an inside broaching or machining operation that would be necessary to form a key that projects inwardly from cylindrical section 16.

The male plug member has a reduced diameter portion 55 on the forward end of cylindrical section 42 that includes a sealing surface 56 which engages O-ring 40 to seal off the interior of the connector.

In operation, assuming the male and female plug members to be separated, the connector is assembled by first moving locking collar 28 rearwardly so that locking balls 36 can be forced into groove 34 when the male plug is inserted into the female plug. Insertion can only be accomplished if the two plug members are aligned so that keyball 52 slides in slot 54. The conductor pins mounted in both the male and female plug members are of a length that they do not contact one another until the male plug member has entered the female plug a sub stantial distance, as illustrated in FIG. 2. Thus, by the time electrical connection is made, with the accompanying likelihood of arcing between the conductor pins, the interior of the connector where the arcing occurs is shielded from the surrounding atmosphere. This feature makes the connector especially useful in environments having an explosive atmosphere. As insertion continues, the male plug is completely installed in the female plug and cavities 37 in the male plug are positioned so as to receive the locking balls when collar 28 slides forward upon being released. This locks the two plug members together and in this position sealing surface 56 of the male plug member engages O-ring 40 in a sealing relation to prevent moisture and the like from entering the interior of the connector.

Disassembly of the connector is accomplished by sliding collar 28 to the rear against the action of spring 30, as shown in FIG. 2, so that the locking balls can be forced out of the cavities 37 in the male plug into groove 34 in the collar. This permits removal of the male plug member and again, as illustrated in FIG. 2, the electrical connection between the conductor pins is broken before the male plug member is completely removed from the female plug, thus isolating any arcing that might occur when the connection is broken.

What is claimed is:

I. An electrical connector having separable male and female plug members;

said male and female plug members each being essentially cylindrical and having conductor pins mounted therein that are arranged to be electrically connected when the plug members are joined;

a keyball mounted in said female plug member; and a longitudinally extending keyway in the outer surface of said male plug member that receives said keyball so as to control the alignment of said male and female plug members during assembly, said male and female plug members being sized such that they can be joined only when said keyball is in said keyway.

2. The electrical connector recited in claim 1 which further includes:

seal means mounted internally in said female plug member, said seal means being positioned so as to be engaged by one end of said male plug member when said male and female plug members are joined, thereby sealing off the interior of said connector.

3. The electrical connector recited in claim 2 wherein the male and female plug members and the electrical conductor pins mounted therein are sized so that the electrical connection between the conductor pins is broken prior to complete removal of the male plug member from the female plug member.

4. The electrical connector recited in claim 2 wherein said seal means includes a groove formed on an interior surface of said female plug member and an O-ring seal mounted in said groove so as to engage an exterior surface of said male plug member in a sealing relation when said male and female plug members are assembled.

5. An electrical connector as recited in claim 4 that further includes locking means for securing said male and female plug members together in an assembled position.

6. An improved electrical connector that includes a male and female plug member that can be easily assembled to make a sealed and shielded electrical connection;

said female plug member comprising:

a cylindrical casing having one end closed and one end open for receiving the male plug member;

a plurality of female conductor pins mounted in a spaced relation in the closed end of the cylindrical casing so that the longitudinal axes of said female conductor pins are substantially parallel to the longitudinal axis of said cylindrical casing, one end of said female conductor pins extending to a point near the. open end of said cylindrical casing and the other ends of said female conductor pins passing through the closed end of said cylindrical casing, said one ends of said female conductor pins having sockets formed therein for receiving male conductor pins;

sealing means mounted in said cylindrical casing so as to engage a male plug member in a sealing relation; and

a keyball mounted in the forward end of said cylindrical casing with a portion of said keyball projecting inwardly into the interior of said cylindrical casing;

said male plug member being sized so as to fit into said female plug member and comprising:

a cylindrical housing having one closed end and one end open and a radially outward extending flange formed on the closed end thereof that functions as a stop when the male plug member is inserted into the female plug member;

a plurality of male conductor pins mounted in the closed end of said cylindrical housing in a spaced relation so that one of the ends of each of said male conductor pins will slide into the cavity of its respective female conductor pin when the male and female plug members are assembled, the other ends of said male conductor pins extending through the closed end of said cylindrical housing, and

a longitudinally extending keyway formed inthe exterior of the cylindrical housing that accommodates the keyball mounted in the cylindrical casing of said female plug member when said male and female plug members are joined.

7. The connector recited in claim 6 wherein said female conductor pins and said male conductor pins have a length such that upon assembly or disassembly of the male and female plug members the cylindrical housing of the male plug member is still partially in the cylindrical casing of the female plug member when the male and female conductor pins are separated, thus isolating from the surrounding atmosphere or arcing that occurs upon making or breaking of the electrical contact.

8. The electrical connector recited in claim 5 wherein said sealing means includes:

a groove in the interior wall of said cylindrical casing at a position near the closed end thereof; and

an O-ring positioned in said groove so as to be engaged in a sealing relation by a male plug member inserted in said female plug member.

9. An electrical connector as recited in claim 7 which further includes locking means for securing said male and female plug members together in an assembled position.

10. The electrical connector as recited in claim 9 wherein said locking means comprises a generally tubular collar disposed around said cylindrical casing and adapted for longitudinal sliding action from a normally forward to a rearward position, said casing having at least one aperture extending radially therethrough rearward of said keybell, a locking ball disposed in each of said apertures, the diameter of said locking ball being greater than the thickness of the wall of said casing, the interior surface of said collar having a groove for each locking ball in said casing, said groove being so located that when said collar is in its forward position the groove is forward of the locking ball and when the collar is in its rearward position the groove is adjacent to the ball so as to receive a portion thereof, the exterior surface of the cylindrical housing of said male plug member having a cavity for each locking ball, said cavity being located so as to receive a portion of said locking ball when said male plug member is fully inserted and said collar is in its forward position, and means for biasing said collar in its normally forward position. 

1. An electrical connector having separable male and female plug members; said male and female plug members each being essentially cylindrical and having conductor pins mounted therein that are arranged to be electrically connected when the plug members are joined; a keyball mounted in said female plug member; and a longitudinally extending keyway in the outer surface of said male plug member that receives said keyball so as to control the alignment of said male and female plug members during assembly, said male and female plug members being sized such that they can be joined only when said keyball is in said keyway.
 2. The electrical connector recited in claim 1 which further includes: seal means mounted internally in said female plug member, said seal means being positioned so as to be engaged by one end of said male plug member when said male and female plug members are joined, thereby sealing off the interior of said connector.
 3. The electrical connector recited in claim 2 wherein the male and female plug members and the electrical conductor pins mounted therein are sized so that the electrical conNection between the conductor pins is broken prior to complete removal of the male plug member from the female plug member.
 4. The electrical connector recited in claim 2 wherein said seal means includes a groove formed on an interior surface of said female plug member and an O-ring seal mounted in said groove so as to engage an exterior surface of said male plug member in a sealing relation when said male and female plug members are assembled.
 5. An electrical connector as recited in claim 4 that further includes locking means for securing said male and female plug members together in an assembled position.
 6. An improved electrical connector that includes a male and female plug member that can be easily assembled to make a sealed and shielded electrical connection; said female plug member comprising: a cylindrical casing having one end closed and one end open for receiving the male plug member; a plurality of female conductor pins mounted in a spaced relation in the closed end of the cylindrical casing so that the longitudinal axes of said female conductor pins are substantially parallel to the longitudinal axis of said cylindrical casing, one end of said female conductor pins extending to a point near the open end of said cylindrical casing and the other ends of said female conductor pins passing through the closed end of said cylindrical casing, said one ends of said female conductor pins having sockets formed therein for receiving male conductor pins; sealing means mounted in said cylindrical casing so as to engage a male plug member in a sealing relation; and a keyball mounted in the forward end of said cylindrical casing with a portion of said keyball projecting inwardly into the interior of said cylindrical casing; said male plug member being sized so as to fit into said female plug member and comprising: a cylindrical housing having one closed end and one end open and a radially outward extending flange formed on the closed end thereof that functions as a stop when the male plug member is inserted into the female plug member; a plurality of male conductor pins mounted in the closed end of said cylindrical housing in a spaced relation so that one of the ends of each of said male conductor pins will slide into the cavity of its respective female conductor pin when the male and female plug members are assembled, the other ends of said male conductor pins extending through the closed end of said cylindrical housing, and a longitudinally extending keyway formed in the exterior of the cylindrical housing that accommodates the keyball mounted in the cylindrical casing of said female plug member when said male and female plug members are joined.
 7. The connector recited in claim 6 wherein said female conductor pins and said male conductor pins have a length such that upon assembly or disassembly of the male and female plug members the cylindrical housing of the male plug member is still partially in the cylindrical casing of the female plug member when the male and female conductor pins are separated, thus isolating from the surrounding atmosphere or arcing that occurs upon making or breaking of the electrical contact.
 8. The electrical connector recited in claim 5 wherein said sealing means includes: a groove in the interior wall of said cylindrical casing at a position near the closed end thereof; and an O-ring positioned in said groove so as to be engaged in a sealing relation by a male plug member inserted in said female plug member.
 9. An electrical connector as recited in claim 7 which further includes locking means for securing said male and female plug members together in an assembled position.
 10. The electrical connector as recited in claim 9 wherein said locking means comprises a generally tubular collar disposed around said cylindrical casing and adapted for longitudinal sliding action from a normally forward to a rearward position, said casing having at least one aperture extending radiAlly therethrough rearward of said keybell, a locking ball disposed in each of said apertures, the diameter of said locking ball being greater than the thickness of the wall of said casing, the interior surface of said collar having a groove for each locking ball in said casing, said groove being so located that when said collar is in its forward position the groove is forward of the locking ball and when the collar is in its rearward position the groove is adjacent to the ball so as to receive a portion thereof, the exterior surface of the cylindrical housing of said male plug member having a cavity for each locking ball, said cavity being located so as to receive a portion of said locking ball when said male plug member is fully inserted and said collar is in its forward position, and means for biasing said collar in its normally forward position. 